<!DOCTYPE html>
<html lang="zh">
<head>
    <meta charset="UTF-8">
    <title>用户登录</title>
    <style>
        /* 全局样式 */
        body {
            margin: 0;
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            background: #f5f5f5;
            font-family: Arial, sans-serif;
        }

        /* 登录容器 */
        .login-box {
            width: 320px;
            padding: 40px;
            background: white;
            border-radius: 8px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }

        /* 标题样式 */
        h3 {
            color: #409EFF;
            text-align: center;
            margin: 0 0 30px 0;
            font-size: 24px;
        }

        /* 输入框组 */
        .input-group {
            margin-bottom: 25px;
        }

        /* 输入框样式 */
        input {
            width: 100%;
            height: 40px;
            padding: 0 15px;
            border: 1px solid #e0e0e0;
            border-radius: 4px;
            font-size: 14px;
        }

        input::placeholder {
            color: #a0a0a0; /* 浅灰色占位符 */
        }

        input:focus {
            border-color: #409EFF;
            outline: none;
        }

        /* 登录按钮 */
        .login-btn {
            width: 100%;
            height: 40px;
            background: #f0f0f0;
            color: #333;
            border: none;
            border-radius: 4px;
            font-size: 16px;
            cursor: pointer;
            transition: background 0.3s;
        }

        .login-btn:hover {
            background: #e0e0e0;
        }
    </style>
</head>
<body>
    <div class="login-box">
        <h3>用户登录</h3>
        <form>
            <div class="input-group">
                <input type="text"
                       name="username"
                       placeholder="账户名">
            </div>
            <div class="input-group">
                <input type="password"
                       name="pwd"
                       placeholder="密码">
            </div>
            <button type="submit" class="login-btn">登录</button>
        </form>
    </div>
</body>
</html>